JP3459080B2 - Recording medium, recording apparatus thereof, and recording medium recording method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable for use in a digital video tape recorder for digitally recording an NTSC video signal or a high-definition television signal represented by high-definition television on a magnetic tape. Recording medium, recording apparatus therefor, and recording medium recording method.

[0002]

2. Description of the Related Art FIG. 17 shows an example of copying (dubbing) in a digital video tape recorder.

In the example of FIG. 17, the deck A is on the reproducing side and the deck B is on the recording side. In the deck A, the video data reproduced from the magnetic tape 71 by the magnetic head 72 is subjected to necessary processing such as demodulation in the reproduction processing circuit 73 and then supplied to the error correction (ECC) circuit 74 to correct the error. Be done. The output of the ECC circuit 74 is A / D converted in the analog processing circuit 75, and is output and displayed as an analog signal on a CRT (not shown) or the like.

The digital data output from the ECC circuit 74 of the deck A is supplied to the deck B via the digital interface. In the deck B, the parity generation circuit 81 adds parity to the data input from the deck A. The data to which the parity is added is modulated by the recording processing circuit 82, supplied to the magnetic head 83, and recorded on the magnetic tape 84.

[0005]

However, since the digital video tape recorder configured so that the digital data can be output as it is can copy digitally any number of times.
There may be social problems from the perspective of copyright protection.

The present invention has been made in view of such a situation, and makes it possible to restrict digital copying.

[0007]

A recording medium to which the present invention is applied is a recording medium in which digital data is recorded on a plurality of tracks, and the tracks are interblock gaps.
Is divided into a first area and a second area which are discontinuous by, and the first area is recorded in the first area.
Sync data and ID data corresponding to the data are recorded.
Which is further digital data recorded scrambled by the key signal, the second region, in its second region
Sync data and ID data corresponding to the recorded data
Data is recorded, and the key signal continues to the ID data.
It is further characterized by being recorded.

[0008] recording medium recording method according to the present invention, there is provided a recording medium recording method for recording digital data on a plurality of tracks of a recording medium, the track, the inter block
It is divided into a first area and a second area discontinuously by a gap , and the first area is recorded in the first area.
Record sync data and ID data corresponding to the data
And further records the scrambled digital data by the key signal, the second region, the serial to the second region
Sync data and ID data corresponding to the recorded data
Data and record the key signal continuously to the ID data.
To record.

This key signal can be changed or randomized for each track and each recording medium. Further, even when the digital data is recorded in the first area without being scrambled, a predetermined key signal set in advance can be recorded in the second area.

A recording medium recording apparatus to which the present invention is applied is
A plurality of tracks of a recording medium are divided into a first area and a second area, digital data is scrambled and recorded in the first area, and digital data is scrambled in the second area. In a recording medium recording device for recording a signal, generating means for generating a key signal for scrambling digital data, and storing the digital data in a memory once and dividing it into blocks, in response to and a blocking means for scrambling, a track, Intabu
First and second regions discontinuous due to lock gap
The first area is recorded in that first area.
The sync data and ID data corresponding to the existing data.
Digit that was recorded and further processed by blocking means
Tal data is recorded, and the second area is recorded in the second area.
Sync data, ID corresponding to the data recorded in
The data is recorded and the key signal is continuously added to the ID data.
It is characterized by further recording .

[0011]

[0012]

[0013]

[0014]

In the recording medium to which the present invention is applied, the interface
-The first region made discontinuous by the block gap
The first area is divided into the second area and the first area.
Sync data and I corresponding to the data recorded in the area
D data is recorded and scrambled by key signal.
Recorded digital data is recorded, and in the second area,
Synth corresponding to the data recorded in the second area
Data and ID data are recorded and linked to the ID data.
Next, the key signal is further recorded. Therefore, it is possible to prohibit the substantial copying of the digital data and to surely restore the scrambled digital data.

In the recording medium recording method to which the present invention is applied , the first block is non-continuous due to the inter block gap.
The first area is divided into the first area and the second area.
Sync data corresponding to the data recorded in the area
And ID data are recorded, and scrambled by a key signal.
The recorded digital data is recorded, and in the second area,
Synth corresponding to the data recorded in the second area
Record data and ID data, and continue to the ID data
Then, the key signal is further recorded. Therefore, it is possible to provide a recording medium that prohibits substantial copying of digital data.

In the recording medium recording apparatus to which the present invention is applied, the memory used for dividing the digital data into blocks is used to scramble the digital data, and the tracks are not blocked due to the inter block gap.
Continuously divided into a first area and a second area, the first area
Corresponds to the data recorded in the first area.
Sync data and ID data are recorded, and
The digital data that has been processed by the
The second area is recorded in the second area.
Sync data and ID data corresponding to the data are recorded.
The key signal is further recorded continuously in the ID data.
Be done . Therefore, the structure can be simplified, the number of parts can be reduced, and an inexpensive recording medium recording device can be realized.

[0017]

[0018]

[0019]

1 and 2 are block diagrams showing a configuration example of a recording system and a reproducing system of a digital video tape recorder to which a recording medium recording device and a reproducing device of the present invention are applied.

In FIG. 1, an analog video signal is input to the input terminal 90. The analog processing circuit 91 A / D converts this analog video signal and supplies it to the scrambler 92 as digital data. The key signal generation circuit 93 generates a key signal used for scrambling and supplies it to the scrambler 92.
The switch 94 selects one of the digital video data input from the input terminal 95 and the scrambled digital video data input from the scrambler 92,
It is supplied to the parity generation circuit 96. The parity generation circuit 96 adds parity to the input digital video data and outputs it to the recording processing circuit 97. The recording processing circuit 97 modulates the digital video data input from the parity generation circuit 96 and outputs it to the magnetic head 98. Further, the recording processing circuit 97 includes a key signal generating circuit 93.
The key signal output by the above is also supplied to the magnetic head 98. A magnetic head 98, which is attached to a rotating drum (not shown) and rotates, receives the input digital video data and key signal at a predetermined timing from the magnetic tape 99.
It is designed to be recorded in.

In FIG. 2, the magnetic head 98 outputs a signal reproduced from the magnetic tape 99 to the reproduction processing circuit 100. The reproduction processing circuit 100 outputs
The key signal is output to the key signal detection circuit 104, the digital video data is digitally demodulated, and the digital data is output to the error correction (ECC) circuit 101. The key signal detection circuit 104 detects a key signal from the input signal.
The error correction circuit 101 corrects an error in the input digital data and outputs it to the descrambler 102.
The descrambler 102 includes a key signal detection circuit 1
The key signal detected by 04 is also supplied. The data descrambled by the descrambler 102 is input to the analog processing circuit 105, D / A converted, and output from the output terminal 106.
Further, the digital data output by the ECC circuit 101 is output to the outside from the output terminal 103 arranged in the preceding stage of the output terminal scrambler 102.

Next, the operation will be described. The analog video signal input from the input terminal 90 is A / D converted in the analog processing circuit 91 to be digital video data. The scrambler 92 scrambles the digital video data input from the analog processing circuit 91 in response to the key signal input from the key signal generation circuit 93. The scrambled digital video data is sent to the parity generation circuit 96 via the switch 94.
Is input to and parity is added. The digital video data whose parity has been restored is digitally modulated in the recording processing circuit 97, and is passed through the magnetic head 98 to the magnetic tape 9.
9 is recorded. At this time, the magnetic head 98 is switched at a predetermined timing to record the key signal on the magnetic tape 98 together with the digital video data.

FIG. 3 shows a simplified positional relationship between the digital video data recorded in this way and the key signal on the magnetic tape 99 (for a more detailed format of the track, refer to FIG. 7). See below). As shown in FIG. 3, a plurality of slanted tracks are formed on the magnetic tape 99. In this track, the video data recording area 9
9A is formed, and a key signal recording area 99B is formed at a position different from the video data recording area 99A. The digital video data is recorded in the video data recording area 99A, and the key signal used for scrambling is recorded in the key signal recording area 99B.

The signal reproduced from the magnetic tape 99 by the magnetic head 98 is input to the reproduction processing circuit 100.
The reproduction processing circuit 100 outputs the key signal of the input signals to the key signal detection circuit 104, digitally demodulates the digital video data, and outputs the digital video data to the ECC circuit 101. The key signal detection circuit 104 detects a key signal from the input signal. The ECC circuit 101 corrects an error in the input digital data and outputs it to the descrambler 102. The descrambler 102 descrambles the digital video data input from the ECC circuit 101 in response to the key signal detected by the key signal detection circuit 104. Descrambler 102
The digital video data descrambled by is input to the analog processing circuit 105, D / A converted,
It is output from the output terminal 106.

Next, the operation of copying will be described. When copying a magnetic tape, two digital video tape recorders having the recording / reproducing system shown in FIGS. 1 and 2 are prepared. Then, one of the digital video tape recorders (having at least a reproducing system) reproduces the digital video data output from its output terminal 103, and the other digital video tape recorder (having at least a recording system) inputs the digital video data to its input terminal 95. Will be supplied from. For convenience of explanation, it is assumed that digital video data reproduced by the reproducing system shown in FIG. 2 is recorded in the recording system shown in FIG.

In the reproducing system, when the magnetic tape 98 is reproduced by the magnetic head 98, the video data recording area 99
The digital video data is reproduced from A and the key signal is reproduced from the key signal recording area 99B. After the digital video data is error-corrected in the ECC circuit 101,
It is output from the output terminal 103. This output terminal 103
Are arranged in front of the descrambler 102. Therefore, the digital video data output from the output terminal 103 remains scrambled data.

The digital data output from the output terminal 103 is input to the parity generation circuit 96 via the input terminal 95 of the recording system and the switch 94. The digital video data to which the parity is added is digitally modulated by the recording processing circuit 97, and the magnetic tape 98 is used by the magnetic head 98.
9 (copy destination magnetic tape) video data recording area 9
Recorded in 9A. In this sense, digital video data can be copied.

However, in the reproducing system, the key signal reproduced from the magnetic tape 99 is supplied to the key signal detecting circuit 104 incorporated in the reproducing system, but is not output from the output terminal 103. Therefore, this key signal cannot be recorded in the recording system. That is, as shown in FIG. 4, the digital video data is recorded (copied) in the video data recording area of the copy destination magnetic tape 99, but the key signal is not recorded in the key signal recording area 99B.

As described above, when the magnetic tape 99 on which the key signal is not recorded is reproduced by the reproducing system, the scrambler 1
The digital video data is input to 02, but since the key signal is not detected, it cannot be descrambled after all. Therefore, even if the video signal output from the analog processing circuit 105 is output to a CRT or the like, substantially no image is displayed. That is, in this sense, copying of digital video data is substantially prohibited.

When the user can select whether or not to scramble, and when not scrambled, the key signal may not be recorded. However, when doing so, some key signal is recorded in the reproducing system to break the scramble, and when this is detected (incorrect key signal is detected, correct video signal should not be output. The configuration for distinguishing between the case) and the case where the key signal is not recorded (when the video signal should be output correctly) becomes difficult. Therefore, when the user chooses not to scramble, it is possible to scramble with a predetermined constant key signal (key signal as default) and record the constant key signal. it can. By doing so, the reproducing system may be configured so as to always descramble in response to the key signal, which simplifies the configuration.

The key signal detection circuit 104 and the descrambler 102 can be integrally formed inside the same IC. By doing so, it is possible to reduce the possibility that the scramble will be broken.

When the general user is not allowed to use the scramble, and only the rental magnetic tape (rental video) is scrambled, the recording system scrambler 72 is omitted. You can By doing so, it is possible to reduce the number of parts in the reproduction system, simplify the configuration, and reduce the cost.

FIG. 5 shows a configuration example of the key signal generation circuit 93. In this embodiment, the random number generator 121
Are latched by the latch circuit 122. The signal SREF synchronized with the rotation of the magnetic head 98 is input to the input terminal 123,
The latch circuit 122 latches the random number at the timing corresponding to this signal SREF. And this latch circuit 12
The random number latched by 2 is supplied to the scrambler 92 and the recording processing circuit 97 as a key signal. In this way, even if the same component is used as the random number generator 121, the random number actually used changes for each digital video tape recorder, and higher protection becomes possible.

That is, since the commercialized random number generator does not generate an infinite number even if it is a random number within the range of the number generated, if it exceeds the range, Eventually, it will have a predetermined period,
In that sense, an absolute random number cannot be generated. However, an absolute random number can be obtained by randomly selecting a predetermined one of the generated numbers. For this random selection, it is possible to use white noise, communication time with the outside, or the like.

In addition to this, for example, if the key signal is changed for each track and for each magnetic tape, higher protection can be realized.

To change the key signal for each magnetic tape,
For example, it can be configured as shown in FIG. In this embodiment, a digital video tape recorder VT
The digital video data output from R ₀ is supplied to the _n digital video tape recorders VTR _{1 to} VTR _n and copied. The key signal generation circuits 93 included in the digital video tape recorders VTR _{1 to} VTR _n are different from each other. As a result, it is possible to simultaneously obtain n magnetic tapes on which the same digital video data is recorded and different key signals are recorded. When copying the next n magnetic tapes, each digital video tape recorder V
The value of the key signal generation circuit 93 included in TR _{1 to} VTR _n may be different from that in the previous case. By doing so, a magnetic tape having 2n different key signals can be obtained. Hereinafter, similar processing may be repeated.

FIG. 7 shows a track format on a magnetic tape as a recording medium of a digital video tape recorder to which the recording medium recording / reproducing apparatus of the present invention is applied. For example, when recording an NTSC video signal,
The data for one frame is recorded on ten tracks of this format. As shown in the figure, in this embodiment, signals are arranged as follows in order from the side (the left side in the figure) where the magnetic head starts contacting the magnetic tape. 4 in the first 455 bytes and the last (the side where the magnetic head separates from the magnetic tape (the right side in FIG. 7))
The 55-byte period is a margin area.
Then, substantial data is recorded in the period of 16089 bytes between these two margin areas.

Next to the first margin area, 60 bytes of T amble are recorded. Since this amble is immediately after the contact with the magnetic head, the PL that generates the clock is generated.
Considering the pull-in of L, it is formed slightly longer than other ambles. In the next 237-byte period, AT
A region F1 is formed. In this area, the pilot signals f1, f2, f _N for tracking are recorded, and the timing sync signal f _T is also recorded. In the A channel track, the signal f _T is recorded in the first 6 × 6 byte section, and the pilot signals f1 and f _N for tracking are recorded in the remaining section. On the other hand, B
In the channel track, the signal f _T is recorded in the first section of 6 × 10 bytes, and the pilot signals f _N and f2 for tracking are recorded in the remaining section. However, the pilot signal f2 is recorded once every four tracks are adapted to the pilot signal f _N are recorded in the remaining three tracks.

In the signal f _T , 6 bytes are recorded as 1 unit (1 block), the first 2 bytes are sync data,
The next 2 bytes are ID data, and the next 1 byte is ID parity (ID _P ). According to the standard, the remaining 1 byte is reserved for future use. Therefore, in the present embodiment, the above-mentioned key signal is recorded here.

[0040]

[Table 1]

As the ID data, the data shown in Table 1 is recorded. That is, a flag (SP / LP) indicating the distinction between the SP mode with a short recording time and the LP mode with a long recording time, and 2-bit data (RTY) indicating the distinction between video, audio or subcode.
PE1 and RTYPE0) are recorded. Further, the position (sync number) from the beginning of the timing sync signal f _T can be known from the 4-bit data (SYNC0 to SYNC4). That is, in this embodiment, the number of timing sync signals f _T is 6 for the A channel track and 10 for the B channel track, but the position is indicated by this sync number.

Next, the principle of tracking control will be described. The A channel track and the B channel track are alternately arranged, and the pilot signal f1 is detected when the magnetic head is reproducing the A channel track. When the pilot signal f1 is detected, after a predetermined time has elapsed from that time, the pilot signal f2 as a crosstalk component from the adjacent track is detected. The recording length of the pilot signal f1 is designed to be short when the pilot signal f2 is detected from the B channel track adjacent to the right side, and the recording length of the pilot signal f2 from the B channel track adjacent to the left side.
Is set to be longer when is detected.

Therefore, by detecting the length of the pilot signal f1, the detected pilot signal f2 is a crosstalk component from the right track or a crosstalk component from the left track. Will be recognized. The level of the crosstalk component from the right track of the pilot signal f2 is temporarily sampled and held. After that, when the next A channel track is reproduced, the level detected as the crosstalk component from the B channel track adjacent to the left side is sampled and held. Then, tracking control is performed so that the levels of both are equal.

After ATF1 as described above, an amble area is formed for a period of 176 bytes. The predetermined period before the amble area is 131-byte IBG.
It is set as a region (inter block gap region). In the subsequent preamble area, a clock necessary for detecting audio data in the audio data recording area that follows is recorded for a period of 45 bytes.

Next to the amble area, an audio data recording area of 1274 bytes (recording area dedicated to audio data) is arranged. In this audio data recording area, uncompressed audio data is recorded as it is. That is, for example, data that is digital data with a sampling frequency of 48 kHz for an analog audio signal of 2 channels and a quantization bit number of 16 bits is directly recorded here (32 kHz, 12
Bits and 4 channels of data are also possible).
However, the formation of the audio data recording area is an option, and the recording can be performed as necessary. As a result, when it is not necessary to record / reproduce a high-quality audio signal, a circuit therefor can be omitted, and a more inexpensive device can be realized. The audio data can be after-recorded.

Next to the audio data recording area, 18
An amble area of a 2-byte period is formed. This amble area includes a 6-byte postamble period following the audio data recording area and a 45-byte preamble period preceding the subsequent video data recording area. And between the two amble areas, 13
A 1-byte IBG area is formed.

The video data recording area has a length of 13377 bytes. In the video data recording area, as will be described later, for example, video data compressed by DCT (discrete / cosine transform) processing is recorded, and audio data compressed by DPCM or the like is also recorded. ing. Audio data in this area is not an option, but is mandatory. That is, even when the audio data is not recorded in the dedicated audio data recording area, by reproducing the audio data recorded together with the video data in the video data recording area,
It is possible to enjoy both video and audio.

Next to the video data recording area, an amble area having a period of 182 bytes is formed. This amble area also has a postamble area (6 bytes) and a preamble area (45 bytes) formed in the same manner as in the amble area formed on the start point side of the video data recording area, and an IBG area between them. (131 bytes) are formed. The postamble area follows the video data recording area, and the preamble area precedes the next subcode recording area.

The subcode recording area is set for a period of 144 bytes. In this area, subcodes associated with video data and audio data recorded in the video data recording area or audio data recording area, such as data and time code required for high-speed access, are recorded.

Next to the subcode recording area, an amble area having a period of 220 bytes is formed. This amble area is also divided into a postamble area (44 bytes) following the subcode recording area and a preamble area (45 bytes) preceding the next ATF2 area, and an IBG area (131 bytes) is formed between them. Has been done.

The area of ATF2 has a period of 237 bytes, and the same data as in the case of ATF1 described above is recorded in this area.

As described above, in the embodiment shown in FIG.
An ATF area (ATF1) is arranged on the side where the magnetic head starts contact with the magnetic tape, and an audio data recording area which is an option is arranged next to the ATF area. And
Following that, a video data recording area in which video data and essential audio data are recorded is arranged.

As described above, formation of the audio data recording area is optional. As a result, when audio data is not recorded here,
Even if the magnetic tape vibrates immediately after the magnetic head comes into contact with the magnetic tape, the reproduced data is not affected because data is not substantially recorded in the audio data recording area. Further, even if the audio data is recorded here, the frequency of the audio data is lower than that of the video data, so that the influence thereof is less than that of the video data. Therefore, it is preferable to arrange the audio data recording area before the video data recording area.

Next, the data format in the video data recording area, the audio data recording area or the subcode recording area will be described with reference to FIGS.

FIG. 8 shows a data format in the video data recording area. In this area,
A sync block having a length of 91 bytes is a recording unit. At the beginning of each sync block, a 2-byte sync and a 3-byte ID are recorded, followed by the subsequent 2
Compressed audio data is recorded during the byte period. As described above, this audio data (Embedded AUDIO) is essential audio data. Following this audio data, video data is recorded in a 76-byte period, and parity is arranged in the last 8 bytes.

The 2-byte audio data, the 76-byte video data and the 8-byte parity are 49
The sync blocks are collected to form a product code. By constructing the product code in this way,
Not only horizontal parity C1 but also vertical parity C
2 is generated, which enables more accurate error correction. In this embodiment, 45 sync blocks are used as audio data and video data, and 4 sync blocks are used as the parity C2.

This (78 + 8) × 49 bytes (= 421
4 bytes of data is 3 blocks (12642 bytes) in the 13377 bytes video data recording area of FIG.
Minutes have been placed. The sync and the ID are arranged in the remaining period of the video data recording area.

9 and 10 show a data format in the audio data recording area in FIG. As shown in these figures, this audio data is also similar to the case of the video data shown in FIG.
Data is recorded with a sync block having a length of 91 bytes as a unit. The first 2 bytes are the sync, and the next 3
The byte is an ID (of which 1 byte (IDp) is the parity of the ID).

This ID is a frame ID (FRID)
In addition to the above, an ID indicating a recording type (for example, "01" in the case of audio) is included by 2 bits (RTTYPE0, RTYPE1). In addition, 9 bits (SYNC0
Through SYNC 8) represent the sync position (sync number) in the frame.

78 bytes following the ID are audio data. Here, as described above, the optional high-quality (uncompressed) audio data is recorded. Following the 78-byte data, 8-byte parity is arranged.

In this way, by making the processing unit the same in the case of video data and the case of audio data (by using sync blocks of substantially the same structure as a unit), the processing circuit of the video data and the audio data are processed. The data processing circuit can be similarly configured,
The hardware configuration is simplified.

As shown in FIG. 9, 78 bytes of audio data and 8 bytes of parity are collected in 14 sync blocks to form a product code.
And in the case of this audio data, FIG.
As shown in, the horizontal parity C1 is arranged at one end (the right end in the embodiment), and the vertical parity C2 is arranged at the center. That is, the upper 5 sync blocks and the lower 5 sync blocks are respectively used as the audio data area, and the middle 4 sync blocks are used as the parity C2 area.

The product code of the video data shown in FIG. 8 (the same as the product code of the audio data shown in FIG. 9)
Shows that three blocks are grouped together as shown in FIG.
Corresponding sync blocks of different blocks are sequentially recorded. That is, for example, after the data of the uppermost sync block (sync block with number 0) of the leftmost block is recorded first, then the uppermost sync block (sync block with number 1) of the next central block is recorded.
Data is recorded, and subsequently, the data of the uppermost sync block (sync block with number 2) of the rightmost block is further recorded. Next, returning to the leftmost block, the second sync block from the top (sync block with number 3) is recorded, and thereafter, the right sync block is recorded sequentially. By recording in this way, it becomes easy to restore the data when the data is dispersed and the magnetic tape is damaged.

As shown in FIG. 9, when the product code of audio data in which the parity C2 is arranged at the center is recorded on the magnetic tape in the order shown in FIG. 14, the format of each track on the magnetic tape is shown in FIG. As shown. That is, an area for recording audio data is formed on the side where the magnetic head of each track starts contact (lower side in the figure) and the side where contact ends (upper side in the figure), and parity C2 is recorded in the middle of the area. Area is formed.

By arranging the parity C2 in the center in this way, even if one (for example, the upper 5 sync blocks) audio data is continuously destroyed, the other (the lower 5 sync blocks) audio data is destroyed. Will remain. Therefore, the destroyed data can be interpolated (corrected) from the remaining audio data. It is empirically known that if the audio data is destroyed every other sample, a signal close to the original signal can be obtained by correcting this. Therefore, as in this embodiment, the area is divided into an upper area and a lower area, and odd-numbered sampling data (L0, L2, L4, ..., R0, R2) is provided in the upper area. , R4
... are arranged (the code indicating the sampling order is 0)
Since it is started from 0, 2, 4, ... Are odd-numbered), even-numbered sampling data (L1, L3, L5, ..., R1, R3, R5 ,.・
If the data in one area is destroyed, a signal close to the original signal can be obtained by correcting the data in the other area.

The intermediate area in which the parity C2 is recorded is
The interval between the two areas in which the audio data is recorded is lengthened to prevent destruction of the audio data over the two areas. In the example of FIG. 11,
An area in which other data (AUX data) is recorded is formed following each recording area of each audio data. By doing so, the interval between the two areas of the audio data can be made longer. The upper AU in the figure
If the X data is arranged immediately before the upper audio data, the interval between the recording areas of the two audio data becomes even longer.

Further, in the embodiment of FIG. 11, NT
Audio data for one frame of the SC system is recorded on 10 tracks (track 0 to track 9), and L is recorded on the first 5 tracks (track 0 to track 4). The audio data of the (left) channel is recorded, and the audio data of the R (right) channel is recorded in the last five tracks (track 5 to track 9). In this way, by arranging the data for the left and right channels separately, after-recording is possible for each channel independently. Further, the data of each channel are interleaved within the five tracks.

FIG. 12 shows a track format when PAL system data is recorded. Figure 1 except that the number of trucks has increased from 10 to 12
The format is the same as in the case of 1.

FIG. 13 shows the data format of the subcode recorded in the subcode recording area of FIG. In this embodiment, a sync block having a length of 12 bytes is a recording unit. The first 2 bytes are the sync, and the next 3 bytes are the ID. Then, the following 5 bytes are used as data, and the subcode is recorded here. The last 2 bytes are used as the parity.

Also in this case, 12 sync blocks having a length of 12 bytes are collected to generate a product code. However, in this case, the horizontal parity C1
Only used.

[0071]

[Table 2]

As described above, as shown in Table 2, the left and right channels (2 channels) of 48 kHz, 16-bit audio data are recorded at the bit rate of 1.536 Mbps in the audio data recording area of FIG. In addition, the AUX data is 0.297303 Mbps
(For NTSC system) or 0.2976Mbp
It is possible to record at a bit rate of s (in the case of the PAL system). The bit rate of this area added with parity, sync, ID, etc. is 3.054545 Mbps (NT
SC method) or 3.0576 Mbps (PA
In the case of the L system). The values in Table 2 are NTS.
This is when the field frequency of the C system is 60 Hz. However, since the field frequency in the case of the NTSC system is not exactly 60 Hz, each bit rate when this is set to an accurate value is 1000/1001 times the value shown in Table 2.

In the video data recording area, 24.
Since audio data, parity, sync, and ID are recorded in addition to 624 Mbps video data, the bit rate of this area is 32.1048 Mbps.

Further, in the subcode recording area, 144
Since the parity, sync, and ID are recorded in addition to the kbps data, the bit rate of this area is 345.6 kb.
ps.

Since the IGB, amble, and ATF signals are recorded on the entire magnetic tape, the total bit rate is 38.6136 Mbps.

Next, with reference to FIGS. 15 and 16, an embodiment of a digital video tape recorder for recording and reproducing data in the above format will be described.

FIG. 15 shows the structure of the recording side. Digital luminance signals Y formed from three primary color signals R, G, B output from, for example, a color video camera (not shown) are input to input terminals 1Y, 1U, and 1V, respectively.
Digital color difference signals U and V are supplied. In this case, the clock rate of each signal is 13.5MHz or 6.75M.
Hz, and the number of bits per sample is 8 bits.

Of this signal, the data amount in the blanking period is removed, and the data amount is compressed by the effective information extraction circuit 2 which extracts only the information in the effective area. Of the output of the effective information extraction circuit 2, the luminance signal Y is supplied to the frequency conversion circuit 3 and the sampling frequency is converted from 13.5 MHz to 3/4 thereof. As the frequency conversion circuit 3, for example, a thinning filter is used so that aliasing distortion does not occur. The output signal of the frequency conversion circuit 3 is supplied to the blocking circuit 5, and the order of luminance data is converted into the order of blocks. The blocking circuit 5 is
It is provided for the block encoding circuit 8 provided in the subsequent stage.

For block coding, DCT, ADRC
(Encoding adapted to the dynamic range) or the like can be adopted. One block has 8 × 8 pixels.

Of the outputs of the valid information extraction circuit 2,
The two color difference signals U and V are supplied to the sub-sampling and sub-line circuit 4, and the sampling frequency is converted from 6.75 MHz to a half thereof respectively, and then two digital color difference signals are alternately selected for each line, and one channel is selected. Is combined with the data of. Therefore, from this sub-sampling and sub-line circuit 4, a line-sequentialized digital color difference signal is obtained.

Subsampling and subline circuit 4
The line sequential output signal is supplied to the blocking circuit 6. Similar to the blocking circuit 5, the blocking circuit 6 converts color difference data in the scanning order of the television signal into data in the block order. Similar to the blocking circuit 5, the blocking circuit 6 converts the color difference data into a block structure of 8 × 8 pixels. The output signals of the blocking circuits 5 and 6 are supplied to the combining circuit 7.

In the synthesizing circuit 7, the luminance signal and chrominance signal converted in the order of blocks are converted into 1-channel data, and the output signal of the synthesizing circuit 7 is supplied to the block coding circuit 8. As the block encoding circuit 8,
Similar to the blocking circuits 5 and 6, a coding circuit (ADRC) adapted to the dynamic range of each block, a DCT
Circuits etc. can be applied. The output signal of the block encoding circuit 8 is supplied to the framing circuit 9 and converted into frame structure data. In the framing circuit 9, the image system clock and the recording system clock are changed.

Further, the digital audio data input from the input terminal 1A ₁ is supplied to the audio processing circuit 18 and subjected to the processing necessary for recording. The output data of the audio processing circuit 18 is supplied to the parity generation circuit 19, and the parity of the product code which is an error correction code is generated (FIG. 9). In this way, the audio data and the parity to be recorded in the audio data recording area described above are supplied to the mixing circuit 12.

The output signal of the framing circuit 9 is supplied to the parity generation circuit 11 via the contact a of the switch 10, and the parity of the product code is generated. The output signal of the parity generation circuit 11 is supplied to the mixing circuit 12. The output signals of the parity generation circuits 19 and 27 are supplied to the mixing circuit 12, respectively. The parity generation circuit 19 generates the parity of the error correction code for the output data of the audio encoding circuit 18. The parity generation circuit 27
An error correction coding process is performed on the subcode input from the input terminal 1S to generate a parity. For the sub-code, only the inner code is used among the product codes having the inner code and the outer code as the error correction code.

The sub-code supplied to the input terminal 1S is
It is generated from the subcode generation circuit 24. Further, the ID or sync generated by the ID generation circuit 25 or the sync generation circuit 26 is supplied to the input terminal 1S. The timing signal generating circuit 23 includes a sub code generating circuit 24, I
The D generating circuit 25 and the sync generating circuit 26 are respectively supplied with necessary predetermined timing signals.

In the mixing circuit 12, the video data, the audio data, and the data in which the subcode is inserted are formed at predetermined positions on one track, which will be described later (FIG. 7). The output signal of the mixing circuit 12 is supplied to the channel encoder 13, and channel coding is performed so as to reduce the low frequency part of the recording data. The output signal of the channel encoder 13 is supplied to the mixing circuit 14.
The ATF pilot signals f1, f2 and f _N are supplied to the mixing circuit 14 from the input terminal 15. This pilot signal is a low frequency signal that can be frequency separated from the recorded data. The output signal of the mixing circuit 14 is supplied to the magnetic heads 17A and 17B (corresponding to the magnetic head 98 in FIGS. 1 and 5) via recording amplifiers 16A and 16B and a rotary transformer (not shown), and a magnetic tape (see FIG. 1
And the magnetic tape 99) in FIG.

On the other hand, the audio data input from the input terminal 1A ₂ (this audio data is
₁ may be the same as or different from the data inputted from ₁ ) and is inputted to the audio compression circuit 21 and, for example, about 300 by DPCM.
It is compressed to kbps. This data is supplied to and stored in the memory 22. The framing circuit 9 controls the memory 22 in the audio data recording area in the video data recording area shown in FIG. 8 to read the audio data stored therein. At this time, the framing circuit 9 switches the switch 10 to the contact b side. As a result, the audio data read from the memory 22 passes through the contact b of the switch 10 and the parity generation circuit 11
And the parity data is added. This data is supplied to the mixing circuit 12, and is supplied to the magnetic heads 17A and 17B for recording in the same manner as described above.

The key signal generation circuit 27 (corresponding to the key signal generation circuit 93 in FIGS. 1 and 5) receives a track pulse corresponding to the number of revolutions of the magnetic heads 17A and 17B, and synchronizes with the key. Generate a signal. This key signal is supplied to the blocking circuits 5 and 6 and the synthesizing circuit 7. The blocking circuits 5 and 6 scramble the digital video data in response to the key signal, and the synthesizing circuit 7 executes the synthesizing process in response to the key signal. Each of the blocking circuits 5 and 6 has a built-in memory for blocking data, and the digital data stored in this memory is divided into blocks and scrambled. In this way, by using the memory for blocking also for scrambling, the number of parts can be reduced.

The key signal output from the key signal generating circuit 27 is also supplied to the sub code generating circuit 24. The subcode generation circuit 24 subcodes the input key signal and outputs it as a subcode. As a result, the key signal is recorded in the ATFs 1 and 2 shown in FIG. The key signal may be recorded in the amble area of FIG. 7, for example.

Next, the structure on the reproducing side will be described with reference to FIG.

In FIG. 16, magnetic heads 17A, 17
The reproduction data from B is supplied to the channel decoder 32 and the ATF circuit 52 via a rotary transformer (not shown) and reproduction amplifiers 31A and 31B, respectively. The channel code is demodulated (decoded) in the channel decoder 32, and the channel decoder 32
Is supplied to the TBC circuit (time axis correction circuit) 33. In this TBC circuit 33, the time-axis fluctuation component of the reproduction signal is removed. In the ATF circuit 52, as described above, the tracking error signal is generated from the level of the crosstalk component of the reproduced pilot signal f2,
This tracking error signal is supplied to, for example, a phase servo circuit (not shown) of the capstan servo.

The reproduced data from the TBC circuit 33 is ECC
It is supplied to the circuits 34, 44 and 46, and the error correction using the product code and the error that cannot be corrected are performed. The ECC circuit 34 performs error correction and error correction on video data (including audio data recorded in the video data recording area), and the ECC circuit 44 corrects error in audio data recorded in the audio data recording area. The ECC circuit 46
Performs subcode error correction.

The reproduced subcode is taken out from the output terminal 43S of the ECC circuit 46. This subcode is supplied to a system controller (not shown) for controlling the operation of the entire VTR.

The output signal of the ECC circuit 44 is supplied to the audio processing circuit 45, processed necessary for reproducing the audio signal, and output from the output terminal 43A ₁ to a circuit (not shown).

The output signal of the ECC circuit 34 is supplied to the frame decomposing circuit 35. The frame decomposing circuit 35 separates the respective components of the block coded data of the video data from each other, and changes the clock of the recording system to the clock of the image system. Each data separated by the frame decomposing circuit 35 is supplied to the block decoding circuit 36, and the restored data corresponding to the original data is decoded for each block.

The decoded data of the video data from the block decoding circuit 36 is supplied to the distribution circuit 37. The distribution circuit 37 separates the decoded data into a luminance signal and a color difference signal. The luminance signal and the color difference signal are supplied to the block decomposition circuits 38 and 39, respectively. Block decomposition circuit 38
And 39 reverse the decoding circuits 5 and 6 on the reproducing side to convert the decoded data in the order of blocks into the order of raster scanning.

The decoded luminance signal from the block decomposition circuit 38 is supplied to the interpolation filter 40. In the interpolation filter 40, the sampling rate of the luminance signal is from 3fs (fs is a color subcarrier frequency) to 4fs (4fs = 13.
5 MHz). The digital luminance signal Y from the interpolation filter 40 is taken out to the output terminal 43Y.

On the other hand, the digital color difference signal from the block decomposition circuit 39 is supplied to the distribution circuit 41, and the line-sequential digital color difference signals U and V are separated. The digital color difference signals U and V separated by the distribution circuit 41 are supplied to the interpolation circuit 42 and are interpolated. Interpolation circuit 4
2 is to interpolate the data of the thinned pixels using the restored video data. From the interpolation circuit 42, digital color difference signals U and V with a sampling rate of 4fs are obtained, and the output terminals 43U, It is taken out to each 43V.

The audio data output from the ECC circuit 34 and recorded in the video data recording area is error-corrected and then supplied to the memory 49 for storage. The ECC circuit 34 also stores an error flag indicating the position of the error that could not be corrected in the memory 49.
Supply to. In the memory 49, the data that is input corresponding to this error flag and that could not be error-corrected is also written. The data written in the memory 49 is supplied to the compression audio decoding circuit 50, and compression decoding is performed. The decoded data is further interpolated by the interpolation circuit 5
1 is supplied. In the interpolation circuit 51, the data corresponding to the error flag is interpolated. Interpolation circuit 5
The output of 1 is output to a circuit (not shown) through the output terminal 43A ₂ .

Further, the signal output from the TBC circuit 33 is input to the f _T signal processing circuit 47. The f _T signal processing circuit 47 detects the sync and ID in the ATF area shown in FIG. 7 from the input signal. Then, the position is determined from the data (sync number) (Table 1) indicating the sync position in this ID, and the counter 48 is operated at a predetermined timing. The counter 48 is the magnetic head 1
Timing signals corresponding to the reproduction positions of 7A and 17B are output from the output terminal 43T. Therefore, the system controller controls after-recording on the basis of the timing signal output from the output terminal 43T.

The f _T signal processing circuit 47 also includes ATF1,
The above-mentioned key signal written in 2 is detected. This key signal is supplied to the block decomposition circuits 38 and 39 and the distribution circuit 41. These circuits perform decomposing processing of blocks and distribution processing and descrambling in response to a key signal. The block decomposing circuits 38 and 39 have a built-in memory for storing data for the block decomposing process. By using this memory also for descrambling, the number of parts can be reduced.

The embodiment of the present invention has been described above.
The number of bytes indicating the length of each area in is an example, and the length can be slightly changed. At this time, in the above embodiment, the ratio of the audio data recording area to the video data recording area is 1: 10.5 (= 1274/133).
77), but this ratio will also change slightly. However, from the viewpoint of efficiency and the like, the ratio is preferably about 1:10.

Although the present invention has been described above by taking the digital video tape recorder as an example, the present invention can be applied to the case of recording data on a recording medium such as a disk.

[0104]

As described above, according to the recording medium to which the present invention is applied, discontinuity is caused by the interblock gap.
Divided into the first area and the second area
Corresponds to the data recorded in the first area
Record sync data and ID data, and use as key signal
The more scrambled digital data is recorded, the second
In the area of, the data recorded in the second area
The corresponding sync data and ID data are recorded, and the ID
Since the key signal is further recorded continuously in the data, it is possible to prohibit the substantial copying of the digital data and surely restore the scrambled digital data.

According to the recording medium recording method to which the present invention is applied, the first recording medium which is discontinuous by the inter-block gap is used.
It is divided into a first area and a second area.
Sync data corresponding to the data recorded in the first area
Data and ID data are recorded, and the
Record the rumbled digital data in the second area
Corresponds to the data recorded in the second area
Sync data and ID data are recorded, and the ID data is recorded
Since the key signal is further set continuously, it is possible to provide a recording medium in which substantial copying of digital data is prohibited.

According to the recording medium recording apparatus to which the present invention is applied, the memory used for dividing the digital data into blocks is used for scrambling the digital data,
Make tracks non-continuous due to interblock gaps
It is divided into a first area and a second area.
Corresponding to the data recorded in the first area of the
Record data and ID data, and use as a blocking means
The digital data that has been processed by
The area corresponds to the data recorded in the second area
Sync data and ID data to be recorded
Further, since the key signal is continuously recorded on the recording medium, the structure can be simplified, the number of parts can be reduced, and an inexpensive recording medium recording device can be realized.

[0107]

[0108]

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a digital video tape recorder to which a recording medium recording device of the present invention is applied.

FIG. 2 is a block diagram showing a configuration of an embodiment of a digital video tape recorder to which the recording medium reproducing apparatus of the present invention is applied.

FIG. 3 is a diagram for explaining the positional relationship on the magnetic tape of digital video data and key signals recorded by the embodiment of FIG.

FIG. 4 is a diagram illustrating a state in which a magnetic tape is copied according to the embodiment shown in FIGS. 1 and 2.

FIG. 5 is a block diagram showing the configuration of another embodiment of a digital video tape recorder to which the recording medium recording device of the present invention is applied.

FIG. 6 is a block diagram showing a configuration example of an apparatus in the case of making different key signals to be recorded for each magnetic tape.

FIG. 7 is a diagram illustrating a track format of the magnetic tape of the present invention.

8 is a diagram illustrating a data format in a video data recording area of FIG. 7.

9 is a diagram illustrating a data format in the audio data recording area of FIG. 7.

FIG. 10 is another diagram for explaining the data format in the audio data recording area of FIG. 7.

FIG. 11 is a diagram showing a track format for recording one frame of audio data of NTSC system.

FIG. 12 is a diagram showing a track format for recording one frame of audio data of the PAL system.

13 is a diagram illustrating a data format in a subcode recording area in FIG. 7.

FIG. 14 is a diagram illustrating the order in which the product codes shown in FIGS. 8 and 9 are recorded.

FIG. 15 is a block diagram showing the configuration of another embodiment of the recording system of the digital video tape recorder to which the recording medium recording device of the present invention is applied.

FIG. 16 is a block diagram showing the configuration of another embodiment of the reproducing system of the digital video tape recorder to which the recording medium reproducing apparatus of the present invention is applied.

FIG. 17 is a block diagram showing a configuration example when a magnetic tape is copied in a conventional digital video tape recorder.

[Explanation of symbols]

2 Effective information extraction circuit 4 Subsample and subline circuits 5, 6 block circuit 8-block coding circuit 9 framing circuit 10, 11 Parity generator 12,14 Mixed circuit 17A, 17B Magnetic head 92 scrambler 93 Key signal generation circuit 98 magnetic head 102 descrambler 103 output terminal 104 key signal detection circuit

Continued front page       (56) References JP-A-62-89275 (JP, A)                 JP 64-7372 (JP, A)                 JP 63-311455 (JP, A)                 JP 63-112870 (JP, A)                 JP-A-63-209071 (JP, A)                 JP 63-191373 (JP, A)

Claims (7)

(57) [Claims] 1. A recording medium having digital data recorded on a plurality of tracks, wherein the tracks are non-continuous due to an inter block gap.
It is divided into a continuous first area and a second area, and the first area is recorded in the first area.
Sync data and ID data corresponding to the data are recorded.
In addition, the digital data scrambled by a key signal is recorded, and the second area is recorded in the second area.
Sync data and ID data corresponding to the data are recorded.
And a key signal further recorded in succession to the ID data . 2. A recording medium recording method for recording digital data on a plurality of tracks of a recording medium, wherein the tracks are separated by an inter-block gap.
Next, it is divided into a first area and a second area, and the first area is recorded in the first area.
Record sync data and ID data corresponding to the data,
Further, the digital data scrambled by a key signal is recorded, and the second area is recorded in the second area.
The sync data and ID data corresponding to the data are recorded,
A recording medium recording method, wherein the key signal is further recorded continuously to the ID data . 3. The recording medium recording method according to claim 2, wherein the key signal is changed for each track. 4. The recording medium recording method according to claim 2, wherein the key signal is changed for each recording medium. 5. The recording medium recording method according to claim 2, 3 or 4, wherein the key signal is randomized. 6. The key signal set in advance is recorded in the second area even when the digital data is recorded in the first area without being scrambled. The recording medium recording method according to claim 2. 7. A plurality of tracks on a recording medium are divided into a first area and a second area, digital data is scrambled and recorded in the first area, and the second area is recorded in the second area. A recording medium recording device for recording a key signal which scrambles the digital data, generating means for generating a key signal which scrambles the digital data, and storing the digital data in a memory once and dividing it into blocks, and the memory not communicate the digital data stored, and a blocking means for scrambling in response to said key signal, the track, the interblock gap
Then, it is divided into a first area and a second area, and the first area is recorded in the first area.
Record sync data and ID data corresponding to the data,
Further, the data processed by the blocking means is applied.
The digital data is recorded, and the second area is recorded in the second area.
The sync data and ID data corresponding to the data are recorded,
The key signal is further recorded continuously to the ID data.
Recording medium recording apparatus characterized by that.